Tesla Energy

Tesla presented Megapack load smoothing for AI data centers to ERCOT's Large Load Working Group (May 2025), claiming it cuts 70%+ of training-load variability. Tesla's amended 2025 annual report shows $430.1 million of 2025 revenue from xAI, primarily from Megapack sales for xAI's data center operations (Electrek, May 2026).

Megapack 3: about 5 MWh per unit, 92.5% round-trip efficiency, 10,000+ cycles, up to 25-year design life and up to 20-year warranty, per Energy-Storage.news on the Texas production start (2026). Megablock: four Megapack 3 units, 20 MWh AC, 91% round-trip efficiency at medium voltage. UL 9540A: the Megapack 2 XL datasheet lists the system as NRTL listed to UL 9540A. Tesla deployed 13.7 GWh in Q3 2026 and plans about 110 GWh a year of Megapack capacity across California (40), Texas (50) and Shanghai (20).

Sources for these notes

Type Editorial supply-chain classification based on the sourced portfolio: system integrator, cell manufacturer, non-lithium or mechanical storage developer, power equipment group, or software and controls supplier.

Integrator 1

Chemistry Main storage chemistry of the flagship product. LFP is lithium iron phosphate; NMC is lithium nickel manganese cobalt oxide; LTO is lithium titanate. Mechanical covers gravity, compressed air and CO2 stores. Mixed means the vendor sells more than one chemistry at scale.

LFP 7

Flagship product The vendor's main grid-scale or commercial storage product line, as the vendor names it.

Megapack 3 and Megablock 1

Energy per unit MWh Energy of one flagship unit (usually a 20-ft container or one enclosure), as the vendor publishes it. Rating basis (usable or nameplate, beginning of life) is in the spec notes.

5 1

Duration Discharge durations the vendor offers at rated power, in hours, as published (for example 2-4 h, or 100 h).

Not published

Deployed GWh Cumulative storage the vendor says it has deployed, delivered or shipped, in GWh, at the date of the cited source. Shipments and installed capacity differ; the spec notes say which one the vendor reports.

Not published

Deployed + contracted GWh Deployed plus contracted or awarded storage (backlog under contract) in GWh, as the vendor states it. Blank when the vendor publishes no contracted figure.

Not published

Cycle life cycles Rated cycle life of the flagship cell or system as the vendor publishes it. Test conditions (temperature, depth of discharge, end-of-life capacity) differ by vendor and are in the spec notes.

10,000 2

Warranty years Longest standard product or performance warranty term the vendor publishes for the flagship system, in years.

20 2

UL 9540 The vendor states a named system in this record is certified or listed to UL 9540. The spec notes identify any earlier product or model-specific scope.

Not published

UL 9540A A cited manufacturer statement or published report describes UL 9540A testing for a named system or cell in the record. Read the spec notes for the model and test level; this is not a blanket certification of all products.

Yes 3

Data center offer The vendor markets a storage product, reference or program for data centers: backup, UPS, grid-interactive UPS, load smoothing for AI training, or bridging power while a grid connection is built.

Yes 4

Parent Owner or parent group when the provider is a subsidiary or joint venture.

Not published

Products Named storage products and cells, with sizes where published.

Megapack 3 (about 5 MWh, 2.5 MW); Megablock (four Megapack 3, about 20 MWh, with transformer and switchgear); Megapack 2 XL (3.9 MWh) 1

Market status Dated ownership, deal or operating context: joint ventures, acquisitions and manufacturing agreements.

Not published

Services Published integration, controls or lifecycle services offered by the provider.

Not published

Reference project A named project and its reported status and capacity. Project capacity is not a product unit rating.

Not published

Headquarters Headquarters city and country only when an explicit cited company statement supports the location.

Not published

1. Electrek: Tesla unveils Megapack 3 and Megablock accessed 2026-11-11
2. Energy-Storage.news: Inside Tesla's Megapack 3 as Texas production begins accessed 2026-11-11
3. Tesla Megapack 2 XL datasheet (Connecticut Siting Council filing) accessed 2026-11-11
4. Tesla: Megapack at Data Centers (ERCOT LLWG, May 2025) accessed 2026-11-11
5. Tesla North: Tesla says Megapacks are almost sold out for 2027 accessed 2026-11-11
6. Tesla deploys 13.7 GWh of energy storage in Q3 2026 accessed 2026-11-11
7. Tesla Q3 2026 Form 10-Q: Megapack and LFP cell manufacturing accessed 2026-11-11
8. Electrek: Tesla reveals $573M web of transactions between Musk's companies (10-K/A) accessed 2026-11-11
9. ESS News: Tesla unveils Megapack 3 and Megablock accessed 2026-11-11